The Core of this Program Project is designed to support all three research projects and to coordinate the flow of information and clinical isolates among the projects. It has three subcomponents: one concentrated on overall management and coordination of the projects, a second focused on development of a shared database and analytic capability, and a third aimed at archiving clinical M. tuberculosis isolates to be channeled to the various projects. The overall goals of the Core are: to maximize the effectiveness of the team of investigators;to facilitate dynamic exchange of ideas, data, and results across projects in the context of their diverse activities;and to disseminate the key findings to a broad audience. The specific aims are: 1) to provide administrative support and management for all projects. 2) to identify and create opportunities for the projects to share data, results, methodological developments, pursue original investigative collaborations, and sustain substantive links with one another and with other ongoing projects. 3) to create an effective and accessible database with well defined methods, common training, and data protection safeguards. 4) to create a safe microbiological laboratory repository for archived drug sensitive and drug resistant M. tuberculosis strains and to conduct molecular genotyping, extraction of DMA and lipids for these strains as well as quality control of drug sensitivity testing for field sites. 5) to disseminate widely scientific methods, instruments and tools, and detailed data and results through multiple avenues.